The invention is based on a hand power tool.
A hand power tool is made known in EP 0 303 651 B2, in fact, a hand-guided power drill having an electric motor located in a housing, via which an insertable tool situated in a tool mount or a drill bit is capable of being driven in a rotating manner. The hand power tool comprises a safety device with which an occurrence of “uncontrolled blockage” of the insertable tool is capable of being detected via a sensor, and a driving of the insertable tool can be halted.
An occurrence of uncontrolled blockage occurs when the insertable tool becomes jammed in the work piece to be worked, the reaction torque acting on the housing exceeds an operator's gripping force, and the housing turns, uncontrolled, around an axis with a certain angular velocity and over a certain angular range. If the operator's gripping force is greater than the existing reaction torque, and/or if the operator grips the hand power tool tightly during blockage, this is an occurrence of “controlled blockage”.
The safety device on the hand power tool made known in EP 0 303 651 B2 comprises a clutch located in a drive train of the hand power tool for interrupting the rotary-driving action when uncontrolled blockage occurs. Moreoever, the safety device comprises a holding device between the clutch and the insertable tool, via which the drive train is interconnected with the housing when uncontrolled blockage occurs. The holding device is formed by an electrically-actuatable brake.